Shank structure for annular hole cutter
US5062748A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 15, 1991 |
| Grant date | Nov 5, 1991 |
| Priority date | — |
| Expiry date | Apr 15, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T408/8973
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A shank structure for holding an annular hole cutter used for drilling a large circular hole, comprising a hollow cylindrical body, a center drill inserted in the inner cavity of the body and clutch means for inhibiting and allowing relative motion between the body and the center drill. In normal or initial state, the body and the center drill are inhibited from their relative motion by the clutch means and, in drilling operation, a central guide hole is first drilled by the center drill. When the guide hole reaches a suitable depth, the clutch means is actuated to allow the relative motion between the body and the center drill and the center drill stops drilling and sinks into the inner cavity of the body. Then, the annular hole cutter secured to the body starts to drill a main hole and, upon completion of the main hole, the center drill is pushed out from the inner cavity by spring action and, at the same time, discharges a disc-shaped chip formed within the annular hole cutter. Accordingly, it gives such an advantage in that centering by the guide hole and discharge of the chip are effected automatically at the same time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.